1. Field of the Invention
The present invention relates to a device and method for measuring snap member detaching force, and a snap chuck. More particularly, the present invention relates to a device and method for applying torque to a snap member attached to cloth of, for example, a garment and then measuring force to detach the snap member from the cloth, and a snap chuck for use in such a detaching force measuring test.
2. Description of the Related Art
Snap fasteners are used in garments, bags, etc. in large quantities. The snap fastener is structured so that a male snap member called a stud member is elastically engaged/unengaged with a female snap member called a socket member (these male and female snap members are generically called a snap member, and include those intended for decoration unless engaged/unengaged). The snap fasteners are generally attached onto one and another surfaces of cloth of a garment etc. which are overlaid each other. In this case, as shown in FIG. 10, a female snap member 1 and a male snap member 2 are fixed to clothes 5, 6 by penetrating a plurality of projections of attachment members 3, 4 called prong members from sides opposite to the surfaces of the clothes 5, 6 facing each other, and then swaging the projections within the outer peripheral parts of the female and male snap members 1, 2.
As small children might swallow the snap members or the attachment members if the snap members attached to the cloth of a garment etc. easily come off, it is necessary to ensure that force to detach the snap members from the cloth is equal to or more than a certain value. Thus, in e.g. sewing plants, the snap member detaching force is inspected and managed so that it is equal to or more than the certain value. In addition, sewing companies in various countries observe the European standard “BS EN71-1: Safety of Toy, Mechanical and physical properties” in which force to detach snap members from cloth is defined to be equal to or more than “90 N for ten seconds”.
Conventional snap member detaching force measurement devices are disclosed in, for example, Japanese Patent Publication Laid-open No. 9-37811 and WO03/102525A1. Such a device comprises cloth holding means for holding cloth around a snap member attached to the cloth, snap chucking means (binding means) for chucking the snap member from its side portion, tension means for pulling the snap member chucked by the snap chucking means from the cloth held by the cloth holding means, and measuring means for measuring the tensile force.
The above snap chucking means includes three jaws whose distal ends are engaged with the side portion of the snap member, a jaw support member for supporting the distal engaging portions of the jaws so that these portions can displace (open/close) inwardly/outwardly in the radial direction of the snap member via a shaft member, and a jaw open/close driving member for putting in and out a tapered portion of the driving member between the jaws from above to open/close the jaw distal engaging portions. Moreover, the snap member is chucked by the jaw distal engaging portions by urging the jaw open/close driving member downward using a spring (spring type) or by moving the jaw open/close driving member which is screwed to a threaded bolt downward along the bolt (screw type).
[Patent document 1] Japanese Patent Publication Laid-open No. 9-37811
[Patent document 2] WO03/102525A1